Topic: Csc Mics distorted but levels good question

[alzeppelin]

I recorded Soul Asylum last night and stood about a foot from the pa stack so needless to say the volume was insanely loud.  During the show the levels on my dr-2d were leaking at -12 db so I figured I was ok. 

After the show I was listening back to the recording and when the vocals were loud they distorted and cracked.  It sounded like the levels were set wrong and the music was clipping but the levels were perfect. 

Has anyone ever experienced something like this?   I just purchased these Csc mics from a member on the board here so I want to make sure the mics aren't defective. 

Any help would be greatly appreciated!

[ilduclo]

mics overloaded because of a bad battery would be my first guess. Were you using a battery box and was the 9v battery changed in the last few months? By the way, the battery will drain even if you're not recording, if the mics are plugged into the box.

[alzeppelin]

I made a point to check the battery before the show and it had plenty of juice.  The mics had been unplugged from the battery box too while in storage.  Would the extreme volume be too much for the battery box to handle?   I mean it was insanely loud being right next to the stack. 

[darktrain]

what recorder were u using

[alzeppelin]

Csc mics-battery box-Tascam dr-2d with mic in

[danny3]

Assuming you keep up with the DR-2d threads, but the questions that come to mind are: did you have input menu level set to LOW, and what level did you have the recorder (left side input buttons) set to?

[alzeppelin]

Level was at 60 and gain was set to mid.  I'm thinking that the gain might have been the problem.  I just never tape at volumes of this level. 

[danny3]

You definately wanted to have the menu INPUT level on LOW! And as has been determined, the side level buttons shouldn't be set lower than @67 (mic in). 

[alzeppelin]

Thanks very much for the input on this.  The gain has been changed to low and will stay that way.

[darktrain]

also you should be using the line in, NOT mic in with a battery box

[datman229]

Level was at 60 and gain was set to mid.  I'm thinking that the gain might have been the problem.  I just never tape at volumes of this level.

I once tried running CSB mic in with gain set to mid on my Tascam Dr07 and it was clipping too even with correct levels.

[acidjack]

Always run line-in unless you can't get sufficient gain.  With MIC-IN that will definitely overload ya.

[rhinowing]

Level was at 60 and gain was set to mid.  I'm thinking that the gain might have been the problem.  I just never tape at volumes of this level.

I once tried running CSB mic in with gain set to mid on my Tascam Dr07 and it was clipping too even with correct levels.

I always run line-in, the mic inputs on the dr-2d are real hot

[co9ol]

Before you tape next time, test it out with a loud home stereo when nobodies home

[Gutbucket]

A home stereo will not produce SPLs high enough to check this.

The advice about using the line-input instead of the mic-input with a battery box is both sound and good general practice, however using the mic-input instead of the line-input on the DR-2d offers the advantage of being able to adjust the input gain while recording and will not be a problem as long as you are getting appropriate levels with the mic-input gain set to LOW and no lower than 67.  It's OK to set it higher than 67.

If you need to go lower than 67 to avoid clipping, that's when you need to switch to using the line-input and give up the ability to change gain while recording.

[fmaderjr]

Thanks very much for the input on this.  The gain has been changed to low and will stay that way.

At an insanely loud concert, even with mic in set to low, I would expect  a good chance of getting a brick walled (distorted) recording anyway. When a recording brick walls, your peaks stay well below 0 dB and the peaks are squared off and flat. When you get a recording like that, reducing your levels further would not have eliminated the problem.

At a concert that loud, you'll get adequate levels going line in with just your battery box and will have a much smaller chance of a brick walled recording. Line in will handle a much higher SPL than mic in without distorting.

If you do that next time out and the recording still brick walls, then either the SPL is too high for your mics or the mics could be broken. 

IMHO, choosing mic in rather than line in is the most likely cause of your problem.

[Gutbucket]

The above is true yet is still misleading concerning use of the the mic-input.
 
It is certainly true that the line-input can accept a hotter signal than the mic-input, yet you only need to switch to using it if the meter shows full-scale peaking when going mic-in/Low/67. 

As long as you are seeing appropriate levels with the DR2d mic-input gain set to LOW and no lower than 67, the meters will be faithful and the recorder will not brickwall, irregardless of the SPL level at the concert.  You can be completely confident in that with no need to second guess it.

Something else in the chain other than the DR2d or the battery box might overload and distort, such as the mics or the preamp if one is used instead of a battery box, but switching to using the line-input on the DR2d will do nothing to prevent that.

This is an important point that many seem to miss.

[fmaderjr]

As long as you are seeing appropriate levels with the DR2d mic-input gain set to LOW and no lower than 67, the meters will be faithful and the recorder will not brickwall, irregardless of the SPL level at the concert.  You can be completely confident in that with no need to second guess it.

Something else in the chain other than the DR2d or the battery box might overload and distort, such as the mics or the preamp if one is used instead of a battery box, but switching to using the line-input on the DR2d will do nothing to prevent that.

I stand corrected. I didn't realize that a level had been determined for the DR2 above which the meters would be faithful, so I was speaking in generalities. I know there are equivalent settings on the recorders I own where you can be sure the meters are accurate (such as 1 or > on the M10), but I've never followed the DR-2 threads much.

[Gutbucket]

That's right, you've got it.. and your advice is good and correct on all other points.

It's especially important with the DR2d in comparison to other recorders since switching to using the line-input gives up the possibility of making gain adjustments on this machine while recording, so many users would prefer using the mic-input whenever possible.

[StarkRavingCalm]

It's worth noting that since you are using the DR-2D, you have the option of recording in DualMode and creating a "safe" copy at a lower level.

But this would only apply to using MicIn.

[Gutbucket]

It's worth noting that since you are using the DR-2D, you have the option of recording in DualMode and creating a "safe" copy at a lower level.

But this would only apply to using MicIn.

Wait!  Before you rely on that function it is important to understand how it works.  And why it's not really that useful for us.

DualMode wouldn't be beneficial unless he had the mic-input level set at least 6dB higher than 67/LOW, assuming he specified the additional dual file is recorded with 6dB lower gain.  Likewise, he would have to set the mic input 12dB higher if he specified the lower level file at -12dB.  If not, he would simply get two brickwalled recordings, one at a lower level than the other.  DualMode can only accommodate for levels which are within the good input range of the recorder.  It is always necessary to make sure the recorder is not peaking with the mic input gain set no lower than 67/LOW.  DualMode doesn't change that.

Complicating things, I'm not sure anyone has determined the dB value of each input level 'number' increment.  There has been no confirmation that increasing the input level by one integer increases the sensitivity of the input by one decibel. Meaning it may not be as simple as setting the mic input gain to 73/LOW (67+6) when DualMode is set to -6dB, or to 79 when DualMode is set ot -12dB.  Someone would need to test that.

As far as I'm concerned it's a useless feature for my uses.  I'd rather just raise the level of the file by the same amount in my editing software after the fact, which achieves exactly the same result.

I bought these recorders specifically for one of the Dual modes, but that's the dual-line mode (4ch) not for the lower level file copy feature which is pretty much worthless in regards to how most of us are using these recorders around here.

[StarkRavingCalm]

Sorry. This is a feature I use alot. Whenever I am only using mics, I always turn on dual mode.
I've never had to go back to the "safe" copy but I have overloaded the mics a couple of times when I have been using DualMode LineIn with a SBD feed.
So this has made me paranoid in that regards.

Mic-only is usually in those stealthing situations so I try to limit interaction with the recorder and this feature is more of a "set it and forget it".

[Gutbucket]

No worries, I just want to clarify how it works and don't want anyone to loose a recording.  You might test all this to confim, but you are most likely better off simply running the gains lower in those "set it and forget it" scenarios and raising the level afterwards on the computer.   That's what I do.

The test would be to set the recorder in dual mode (say -12dB) and mic input gain set at 67/LOW, then record something into the mic input which is clips the meters and keeps the the peak light mostly lit.

The 0dB file should show flat-topped waveforms and sound distorted.  The key will be looking at and listening to the -12dB file.  Is it also flat-topped and distorted and simply recorded 12dB lower in level or is it clean?